1. Field of the Invention
The present invention relates to a ferrite composition preferably used for electronic components such as an inductor element and the like, and an electronic component such as an inductor element to which said ferrite composition is applied.
2. Description of the Related Art
In recent years, reduction in size and weight for various kinds of electronic apparatuses such as a portable apparatus and the like are progressed rapidly. In order to respond this situation, demands of reduction in size and weight, and high performance for electronic components used for electric circuits of various kinds of electronic apparatuses are rapidly increased.
In an electronic component such as an inductor element, a number of ferrite compositions having good magnetic characteristic are used as a magnetic material.
Such material needs to show not only high magnetic permeability but also a small decrease in magnetic permeability to which direct current (DC) is applied, namely, a good superposed DC characteristic.
For example, Japanese Patent Publication No. 2005-145781 discloses that by adding specific amount of silicon or silica to NiCuZn based ferrite, inductance to which direct current is superposed is increased.
Also, Japanese Patent Publication No. 2005-213092 discloses that by adding specific amounts of ZrO2 and SiO2 to NiCuZn based ferrite, resistance property to thermal shock and the like are increased.
Meanwhile, an electric apparatus to which electronic components such as an inductor element and the like are mounted, is used under various environments, it is required that change of magnetic permeability of the inductor element is small through wide temperature range, namely, a temperature characteristic of the magnetic permeability is good.
Also, when a multilayer inductor is composed of the inductor, the multilayer inductor needs to be fired at a lower temperature which is lower than a melting point of Ag which is generally used as a coil conductor (for example, 900° C. or so).
However, in the Japanese Patent Publication No. 2005-145781, a temperature characteristic of the magnetic permeability is not considered at all. Also, although it is described that, due to atomization of raw materials, it is possible to fire the ferrite at 900° C. or so by adding SiO2 only. However, that has been in fact difficult to be achieved.
Also, in the Japanese Patent Publication No. 2005-213092, in addition that the temperature characteristic of the magnetic permeability is not considered at all, and a firing temperature is 1000° C. or more, it was difficult to perform a lower temperature firing.